<h2>Problem 160</h2>
<div style="color:#666;font-size:80%;">07 September 2007</div><br />
<div class="problem_content">
<p>For any N, let f(N) be the last five digits before the trailing zeroes in N!.<br />
For example,</p>
<p style="margin-left:50px;">9! = 362880 so f(9)=36288<br />
10! = 3628800 so f(10)=36288<br />
20! = 2432902008176640000 so f(20)=17664</p>
<p>Find f(1,000,000,000,000)</p>
</div><br />
